Featured Wine coaster

I picked this up today for £1. I just assumed it was silver plate at first but after polishing it and discovering a mark, I think it might well be solid silver. Not much weight to it, but always nice to find some of it. What do you reckon?

 

Is the mark IS?
If so, I'm thinking the coaster is from one of the many "International Silver" consortium of companies, many of which made silverplate... but that was an American thing, I think.
But WDIK!

 

Could well be true. If so you have truly broke my heart. :0(

 

I'm over it already

 

It doesn't look like an 'I' to me. It looks rounded at the bottom (or top if the mark is upside down...)

 

I was looking at letter date codes but then realised that there are no other marks such as crowns, anchors etc so god knows. It looks like there is some kind of shield shape indent that surrounds it though.

 

An actual close-up pic of the mark might be useful. The magnification of the current photos probably shows a distorted image of the actual mark. The S doesn't even look like an S in the "close up" photo I posted.

 

The mark is on a fold in the metal so its a bit awkward catching it in the light properly. Maybe these are better?

 

Much better .... but I still have no idea what I'm seeing in that mark

 

We need to keep searching . . . but gut feeling says it might be silver, not plated. I'm basing that opinion on the construction of the rest of coaster. It's better constructed than most wine coasters I've seen.

 

It looks like half of it is missing. Possibly one or two letters in a cursive style font maybe?

 

Thanks. I'm starting to think its not silver and likely plate. I did a couple of tests this morning and getting a mix of muddy browns, blues and yellows. Also in the crease near the base their is some green corrosion so likely a cupric alloy underneath and maybe lead/tin solder giving the blue and green colours with the test. It rings like a bell so maybe brass or copper. It would still be nice to know what the mark is though. Ill keep looking.

 

Maybe it says 18? A manufacturer's code?

 

I forgot all about the magnet test. I actually have one so i will try that thanks. I thought they worked because silver is so electrically conductive. The Induced eddy currents oppose the magnetic field in the magnet..maybe

 

Georg Jensen?

 

That shape of the mark reminded me of something Id seen on here . Take a look at this ... https://www.antiquers.com/threads/hallmark-help-on-silver-plate-warming-dish.53407/